<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <script>
        var input_username = prompt("请输入用户名");
        var input_password = prompt("请输入密码");
        if (input_password == "123456" && input_username == "admin") {
            alert("登录成功");
        } else {
            alert("密码或者用户名错误");
        }
    </script>
</body>

</html>